DESCRIPTION: This is a proposal to test the hypothesis that the ornithine decarboxylase-antizyme gene (ODC-Az) is a tumor suppressor gene in oral cancer Under Aim 1 the tumor suppressing-potential will be evaluated in malignant hamster oral keratinocytes by introducing the gene in an inducible retrovirus system. Under Aim 2 the regulatory region of the gene will be examined in orde to find if loss of expression is due to changes in that region.